ettes or cigarettes with cardboard holder) with high (low) concentration of nicotine, aboriginals (Emigrants), white, dark-or yellow-skinned, etc. It would require enormous efforts and still would not be justified, since the world is continually changing and one would have to do this work every time again. It's all the more so impossible to develop statistical specifications/standards for infinite number of groups of subjects in the course of dynamic processes, for example, physical activities and at different phases of pathological processes, etc., when the number of values ​​of each separate parameter is quite large. When the system's details are completely uncertain, although the variants of the system's reaction and their probabilistic weighting factors are known, statistical mathematical model of system arises. Inaccuracy of these models is of fundamental character and is stipulated by probabilistic character of functions. In process of studying of the system details of its structure become apparent. As a result an empirical model emerges in the form of a formula. The degree of accuracy of this model is higher than that of statistical, but it is still of probabilistic character. When all details of the system are known and the mechanism of its operation is entirely exposed the deterministic mathematical model appears in the form of the formula. Its accuracy is only stipulated by the accuracy of measurement methods. Application of statistical mathematical models is justified at the first stages of any cognition process when details of phenomenon in question are unknown. At this stage of cognition a "black box" concept is introduced when we know nothing about the structure of this "box", but we do know its reaction to certain influences. Types of its reactions are revealed by means of statistical models and thereafter, with the help of logic, details of its systems and their interaction are becoming exposed. When all that is revealed, deterministic models come into play and the evaluation of the systems 'functions is made not on the basis of tabular data, but on the basis of due curve of the system function. Due curve of a system's function is a due range of values ​​of function of the given concrete system in the given concrete subject, with its load varying from minimum to maximum. Nowadays due curves are scarcely used, instead extreme minimum and maximum due values ​​are applied. For example, due ventilation of lungs in quiescence state and in the state of peak load. For this purpose maximum load is given to individuals in homotypic groups and pulmonary ventilation in quiescence state and in the state of peak load is measured. Following statistical processing due values ​​of pulmonary ventilation for the conditions of rest and peak load are obtained. The drawback of extreme due values ​​consists in that this method is of little use for the patients. Not all patients are able to norma...
